Thermal Cleaning for Painted Mufflers

Ah, so the way of fire is your path, my pupil?

Pondering the pure essences of metal and fire, and knowing that a can of spray-on high-temp stove black (available at your local hardware
store) will restore the surface finish, you choose to follow the simple chemistry of C + O2 => 2CO. Knowing full well that
this process will release quite a bit of deadly carbon monoxide, you ponder your options....

A Nice Little Campfire

What a big fire you have, Grandmother

The better to cook you with, my dear....

Picking up a cheap $20 BBQ set at the end of summer may not have been the best culinary purchase you ever made, but it's coming in
handy now. You lay down a bed of charcoal, and light 'em up. A nice thick bed. About 3 coals deep. While it gets good and hot, you prepare
your muffler for the cleansing flames by thrusting a metal coat hanger up it's exhaust pipe.

As you lay the muffler on the burning coals, and heap the red embers around it, you can hear the muffler pop at the metal expands, and
the carbon inside begins to flake off in chunks, and slowly consume itself in the heat.

About a half hour later, the muffler has reached a nice cherry red. Lifting the blazingly hot muffler from the inferno with a pair of tongs
placed artfully into the coat hanger, you gently lower it's hellish carcass to the concrete (or the back of a cookie sheet turned lip-side down).

An hour later, after the burgers are done (What?!? You considered wasting the opportunity to Burn Meat?) , you gently shake out the ash
from the muffler, and gaze in wonder at how clean it is.

Abusing A Self-Cleaning Oven

Apartment life has it's advantages, but a place to put a proper BBQ isn't one of them. However, you are in luck to have a
(functional) self-cleaning oven. With the proper safety techniques, this can clean your muffler just as well any anything
else.

After putting a layer of aluminum foil on the lower rack of your oven to catch any oil or other drips, you gently place your
muffler above the foil, on the upper rack. Taking advantage of your kitchen window to provide ventilation (remember,
we're going to making a lot of carbon into carbon monoxide gas!), you close the door, engage the door latch
(don't want to fill the house with smoke!) and start the self-cleaning cycle.

Three to four hours later, after seeing that great new flick at the.. eh hem.. art house theater, you come back to a clean
oven, and an ash filled muffler.

Just empty the ash from the muffler into the trash, and it's clean as a whistle (ok, a dusty whistle that's been on
grandma's knick-knack shelf for 30-some-odd years, but still clean).

Rust-Out City

At first, life seems good. The moped back up to par, and she purrs like a kitten. But, insidiously, it begins.

First, there's the sudden shower out of nowhere. No problem, you say, as you ride through the puddles.

However, the enemy rust has begun to show his face. Creeping into your muffler, accelerated by the
below boiling point temperatures at the end of the exhaust stack, the bastard gets his tendril into
your precious moped.

From there, it's a sad story of regret, removal, angst, and a long search through eBay...

Stove Black Keeps The Rust Back

Knowing good and well that mufflers and rust don't mix (having seen firsthand what it did to Uncle Steve's
1978 Chevy), you pop by the local hardware store and pick up a can of high temperature stove black.

A good substitute for stove black is Rust-Oleum Specialty High heat enamel spray paint. It can be purchased for less than $5.00 at any hardware store in the spray paint section.

A couple of nice even coats, and the muffler looks as good as - no - better - than new, and willing to
give you many years of excellent service.

Chemical Cleaning for Chrome Mufflers

What the hell? Why didn't you finish this tutorial, you goof?

How's about I finish it-ish
I never tried chemical cleaning. Did you? I've heard of:

Lye

'Seafoam' cleaner/fuel stabilizer/miracle fluid

Carb cleaner

What worked for you? What ate off the chrome? What didn't work at all?

Fill out this section with your hard earned experience.

I sprayed a lot of degreaser down the muffler and let it soak in for about fifteen minutes and use a few rags and shoved them in there twisted them around and pulled them back out. Ran water through the pipe and repeated the process a few times. Worked good for me. Even got a lot of the crap off the chrome as well.

carb cleaner works...but you would need a lot of it

I used foaming automotive engine cleaner, aerosol degreaser, some water, a rag, a dowel and a screwdriver. I disassembled the entire exhaust, and put the parts into a bucket. Then, I cleaned them one at a time. The silencer cleaned up well with degreaser and a rag. The muffler had engine cleaner sprayed into it, then got to sit 5 minutes. The foam breaks down and cleans at the same time, so you can pour the liquid (formerly foam) into the bucket when it's done cleaning. I noticed it got most of the big stuff clean, but there was still oily residue in the muffler, so I put some degreaser on a rag, put the rag on the dowel, then ran the rag-and-dowel assembly throughout the inside of the muffler. Cleaned it right up. The pipe from the cylinder to the muffler was a bit harder to do due to the curve in it, but I scraped a bit of carbon off with a screwdriver, then sprayed the engine cleaner inside and waited until it was clean. Then rinse with water, dry, and reassemble.